MECHANISM OF DEATH 



285 



ment react as if all cell contents formed one continuous 

 fluid, as if cell-walls and separating medium did not 

 exist. This seemed justified because the genes do not 

 react with one another, but only with molecules which 

 are plentiful in each cell. 



Let us assume that a large number of uniform bacteria 

 were heated to 55°C., and at this temperature, the 

 most sensitive gene molecule would be hydrolyzed at 



Fig. 32. — Order of death computed for organisms which are killed by the 

 reaction of r = 1, 2, 3, 4, 6, 12, or 100 molecules per organism. The dotted 

 line is the order of death for r = 1 molecule, but with three different grades 

 of resistance. 



the rate of 90% of all such molecules per minute. At 

 the end of this time, only 10 % of the cells will have this 

 gene intact ; the 90 % will have lost the power to multiply 

 because one of the genes is damaged beyond repair. 

 During the second minute, 90% of the undamaged cells 

 will again suffer the hydrolysis of the special gene, i.e.. 



